Modular intelligent sensing electric energy metering box integrated with IGBT module temperature control protection

Abstract

The application relates to the technical field of electric power metering equipment, in particular to a modular intelligent sensing electric energy metering box integrated with IGBT module temperature control protection, which comprises a box body, an incoming line metering module, an IGBT power control module, an integrated heat management system, an IGBT driving and protection unit, an outgoing line module, an intelligent sensing and control unit and an internal bus system. The inside of the box body is divided into an incoming line metering chamber, a power control chamber and an outgoing line chamber through a metal partition plate, and an electromagnetic shielding layer is arranged between the power control chamber and the incoming line metering chamber and the outgoing line chamber. The application realizes fine heat management of the IGBT module by adopting a thermoelectric coupling prediction model, avoids device failure caused by heat accumulation and prolongs the service life of the equipment; the modular design allows the IGBT power control module with faults to be replaced online without interrupting the power supply of the main bus, and the power-off time is significantly shortened.

Description

Technical Field

[0001] This invention relates to the field of power metering equipment technology, specifically to a modular intelligent sensing power metering box with integrated IGBT module temperature control protection. Background Technology

[0002] Traditional electricity metering boxes have limited functionality, mainly consisting of a circuit breaker, an electricity meter, and a simple housing, capable of only basic electricity distribution, metering, and overcurrent protection. Patent application CN202610036503.7 discloses a remotely controllable intelligent electricity metering box, including an embedding component, a box body, and a enclosure mechanism. The embedding component has an internal mounting chamber for embedding into the box body, with the side of the box body fitting against the inner wall of the mounting chamber. The embedding component is embedded into the wall. An enclosure mechanism is installed at the front end of the embedding component, connected to the top area of ​​the embedding component, and used to cover the front area of ​​the box body. This design allows for remote control of the internal box body to move in case of overheating or even open flame, forming a near-closed structure within the internal space. Ultimately, the sealing effect blocks oxygen input, achieving fire extinguishing. This process also protects the internal smoke sensor and prevents external rainwater and dust from entering the box, enhancing the protection of the internal electrical equipment.

[0003] Traditional electricity metering boxes suffer from the following drawbacks: a lack of effective temperature control for core heat-generating components, leading to equipment aging or burnout due to high temperatures in summer; and a predominantly monolithic structure requiring a complete power outage for maintenance, resulting in poor expandability. While some improved metering boxes have added fans or simple communication modules, they have not addressed the thermal management and electromagnetic compatibility challenges arising from the integration of power devices such as IGBTs at the system level. Summary of the Invention

[0004] In order to overcome the deficiencies in the prior art, the present invention aims to provide a modular intelligent sensing power metering box with integrated IGBT module temperature control protection, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a modular intelligent sensing power metering box with integrated IGBT module temperature control protection, including a box body. The box body is divided into an inlet metering chamber, a power control chamber and an outlet chamber by a metal partition. An electromagnetic shielding layer is provided between the power control chamber and the inlet metering chamber and the outlet chamber.

[0006] The incoming line metering module is pluggably installed in the incoming line metering chamber and includes an incoming line terminal block, an intelligent power metering chip, and a current and voltage sampling unit.

[0007] At least one IGBT power control module is pluggably installed in the power control room, including an IGBT power unit, for performing circuit on / off control and power quality regulation;

[0008] An integrated thermal management system includes a heat sink that is thermally connected to the IGBT power unit, a first temperature sensor located near the IGBT chip, a second temperature sensor located at the heat sink outlet, and a variable speed fan driven by an intelligent control unit.

[0009] The IGBT driver and protection unit integrates hardware-based overcurrent fast protection and software-based temperature rise prediction protection.

[0010] The outgoing module is pluggably installed in the outgoing room and includes several outgoing switches;

[0011] The intelligent sensing and control unit is communicatively connected to the incoming line metering module, IGBT power control module, and outgoing line module, respectively. It includes a data processing module for receiving voltage, current, and temperature data and performing edge computing; a thermoelectric coupling prediction module, embedding a thermal network model of the IGBT module, for calculating heat generation based on real-time current and dynamically predicting future trends in IGBT junction temperature in conjunction with heat dissipation conditions; and a communication module for data interaction with an external master station or maintenance terminal. The intelligent sensing and control unit transmits control signals to the IGBT drive and protection unit via optical fiber to achieve electrical isolation between signals and power.

[0012] The internal bus system uses tin-plated copper busbars that run through the incoming metering chamber, power control chamber, and outgoing chamber to provide electrical connections for the incoming metering module, IGBT power control module, and outgoing module.

[0013] As a further improvement to this technical solution, the integrated thermal management system also includes a phase change thermal storage device, which is closely fitted to the radiator to absorb the instantaneous impact heat generation of the IGBT power unit and smooth out temperature fluctuations; the phase change thermal storage device is filled with paraffin-based composite phase change material, and its phase change temperature is set to 85-95℃.

[0014] As a further improvement to this technical solution, the IGBT drive and protection unit also includes a dynamic dead time adjustment circuit. The intelligent sensing and control unit dynamically adjusts the IGBT drive dead time according to the junction temperature data collected by the first temperature sensor: when the junction temperature is higher than the first threshold, the dead time is increased to reduce switching losses; when the junction temperature is lower than the second threshold, the dead time is reduced to improve the output waveform quality.

[0015] As a further improvement to this technical solution, the thermal network model embedded in the thermoelectric coupling prediction module is a Foster fourth-order RC network model, with time constants set to τ1=0.1s, τ2=0.5s, τ3=2.0s, and τ4=5.0s, respectively, to simulate the transient thermal response characteristics of the IGBT module; the prediction module updates the junction temperature prediction value at a frequency of 10Hz, and the prediction time domain length is 5 seconds.

[0016] As a further improvement to this technical solution, the intelligent sensing and control unit also includes a fault waveform recording module. When the IGBT power control module triggers protection or electrical parameters change abruptly, it automatically records the voltage, current and temperature waveform data for the 10 cycles before the fault and the 5 cycles after the fault, and stores them in a non-volatile memory for the operation and maintenance terminal to read and analyze via Bluetooth or RS485 interface.

[0017] As a further improvement to this technical solution, the power control room is provided with multiple parallel modular guide rails, the bottom of the IGBT power control module is provided with a slider that cooperates with the guide rails, the rear end is provided with a blind-plug power connector, and the front end is provided with a handle with a self-locking function; after the IGBT power control module is inserted, it automatically establishes an electrical connection with the internal bus system through the blind-plug power connector.

[0018] As a further improvement to this technical solution, the intelligent sensing and control unit also includes a self-identification module. When a new IGBT power control module is inserted into the power control room, the self-identification module automatically identifies its model, rated current, and thermal network parameters by reading the storage chip inside the module, and automatically downloads the corresponding control algorithm to achieve plug-and-play functionality.

[0019] As a further improvement to this technical solution, the intelligent sensing and control unit implements a graded temperature control protection strategy, including:

[0020] Level 1: When the predicted junction temperature is below 80°C, maintain the current fan speed or stop operating.

[0021] The second stage involves actively cooling the fan by linearly increasing the PWM duty cycle based on the predicted temperature rise slope when the predicted junction temperature reaches 80°C but is below 100°C using a PID algorithm.

[0022] The third level is when the fan is at full speed and the predicted junction temperature is 100°C but below 125°C, the derating operation strategy is implemented to reduce the switching frequency or output current limit of the IGBT.

[0023] Level 4: When the predicted junction temperature reaches 125℃, the IGBT shutdown protection is immediately triggered, and a fault alarm is uploaded.

[0024] As a further improvement to this technical solution, the communication module includes a 4G / 5G full network connectivity module, an HPLC high-speed power line carrier module, and a Bluetooth 5.0 module; the 4G / 5G module is used for remote data interaction with the distribution network automation master station, the HPLC module is used for local communication with the intelligent terminal in the distribution area, and the Bluetooth 5.0 module is used for on-site debugging and data reading by maintenance personnel.

[0025] As a further improvement to this technical solution, the temperature control protection method of the modular intelligent sensing energy metering box includes the following steps:

[0026] S1. System initialization: Self-test the IGBT power control module, read its factory parameters and initialize the thermal network model.

[0027] S2. Data acquisition: The load current i(t), IGBT module case temperature Tc(t) and ambient temperature Ta(t) are acquired in real time at a sampling rate of not less than 10kHz.

[0028] S3, Junction Temperature Prediction: Input the collected data into the preset Foster fourth-order thermal network model to calculate the current junction temperature and predict the junction temperature change curve Tj_pre(t) within the next 5 seconds.

[0029] S4. Hierarchical decision-making: Execute different control actions based on the maximum value of Tj_pre(t).

[0030] If max[Tj_pre(t)] < 80℃, then execute step S41 to maintain or reduce the fan speed;

[0031] If 80℃≤max[Tj_pre(t)]<100℃, then execute step S42, and linearly increase the fan PWM duty cycle according to the temperature rise slope using the PID algorithm;

[0032] If 100℃≤max[Tj_pre(t)]<125℃ and the fan is already at full speed, then execute step S43 to reduce the IGBT switching frequency or output current limit.

[0033] If max[Tj_pre(t)]≥125℃, then execute step S44 to immediately shut down the IGBT and report the fault.

[0034] S5. Fault waveform recording and uploading: When step S44 is triggered or a sudden change in electrical parameters is detected, the waveform data of 10 cycles before and after the fault is automatically recorded and uploaded to the distribution network master station through the communication module.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1. This modular intelligent sensing power metering box with integrated IGBT module temperature control protection achieves refined thermal management of IGBT modules by adopting a thermoelectric coupling prediction model, avoiding device failure caused by heat accumulation and extending equipment life; the modular design allows for online replacement of faulty IGBT power control modules without interrupting the main bus power supply, significantly shortening power outage time.

[0037] 2. This modular intelligent sensing energy metering box with integrated IGBT module temperature control protection uses dynamic dead time adjustment technology to ensure that the IGBTs maintain low switching losses even in high-temperature environments, thus widening the operating temperature range of the equipment. Furthermore, the fault recording function provides detailed data for post-accident analysis, improving the accuracy of power grid fault diagnosis. Attached Figure Description

[0038] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, will select various possible shapes and proportions to implement the invention according to specific circumstances.

[0039] Figure 1 This is a block diagram showing the modular distribution of internal components of the power metering box of the present invention;

[0040] Figure 2 This is a flowchart illustrating the temperature control and protection process of the power metering box of the present invention.

[0041] Figure 3 This is a comparison graph of the junction temperature change curves of the present invention. Detailed Implementation

[0042] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art will conceive of any possible variations of the invention, all of which should be considered within the scope of the invention. The terms "installation" and "connection" should be interpreted broadly, referring to direct connection as well as indirect connection through an intermediate medium.

[0043] The terms "central axis," "vertical," "horizontal," "front," "rear," "upper," "lower," "left," "right," "top," "bottom," "inner," and "outer" used herein to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of the invention, "a number" means two or more, unless otherwise explicitly specified.

[0044] Please see Figures 1-3 As shown, this invention provides a modular intelligent sensing energy metering box with integrated IGBT module temperature control protection, including a box body, an incoming line metering module, an IGBT power control module, an integrated thermal management system, an IGBT drive and protection unit, an outgoing line module, an intelligent sensing and control unit, and an internal bus system. The box body is divided into an incoming line metering chamber, a power control chamber, and an outgoing line chamber by metal partitions, and an electromagnetic shielding layer is provided between the power control chamber and the incoming line metering chamber and the outgoing line chamber.

[0045] The incoming line metering module is pluggably installed in the incoming line metering chamber and includes incoming line terminals, an intelligent energy metering chip, and a current and voltage sampling unit. The module is inserted via a guide rail, and its rear connector connects to the incoming end of the internal bus system. The module integrates a high-precision current / voltage transformer and a metering chip (such as RN8302B), and metering data is directly uploaded to the intelligent sensing and control unit via the onboard bus.

[0046] At least one IGBT power control module is installed in the power control room in a pluggable manner. It includes IGBT power units for performing circuit switching control and power quality regulation. It adopts a half-bridge or full-bridge topology and is connected to the incoming and outgoing lines through an internal bus system.

[0047] Specifically, the integrated thermal management system includes a heat sink thermally connected to the IGBT power unit, a first temperature sensor located near the IGBT chip, a second temperature sensor located at the heat sink outlet, and a variable-speed fan driven by an intelligent control unit. The IGBT is directly sintered onto the heat sink, which employs a needle-fin design to increase the heat dissipation area. The first temperature sensor is a surface-mount NTC sensor, closely attached to the DCB substrate below the IGBT chip; the second temperature sensor is located at the heat sink outlet; and the variable-speed fan is a PWM-controlled axial flow fan.

[0048] Furthermore, the integrated thermal management system also includes a phase change thermal storage device, which is closely fitted to the radiator to absorb the instantaneous impact heat generated by the IGBT power unit and smooth out temperature fluctuations. The phase change thermal storage device is filled with paraffin-based composite phase change material, and its phase change temperature is set to 85-95℃.

[0049] Specifically, the intelligent sensing and control unit is communicatively connected to the incoming line metering module, the IGBT power control module, and the outgoing line module. It includes a data processing module for receiving voltage, current, and temperature data and performing edge computing; a thermoelectric coupling prediction module, which embeds a thermal network model of the IGBT module, for calculating heat generation based on real-time current and dynamically predicting future trends in IGBT junction temperature in conjunction with heat dissipation conditions; and a communication module for data interaction with an external master station or maintenance terminal. The intelligent sensing and control unit transmits control signals to the IGBT drive and protection unit via optical fiber to achieve electrical isolation between signals and power.

[0050] The thermal network model embedded in the thermoelectric coupling prediction module is a Foster fourth-order RC network model, with time constants set to τ1=0.1s, τ2=0.5s, τ3=2.0s, and τ4=5.0s, respectively, to simulate the transient thermal response characteristics of the IGBT module; the prediction module updates the junction temperature prediction value at a frequency of 10Hz, and the prediction time domain length is 5 seconds.

[0051] Furthermore, the intelligent sensing and control unit also includes a fault waveform recording module. When the IGBT power control module triggers protection or electrical parameters change abruptly, it automatically records the voltage, current, and temperature waveform data for the 10 cycles before the fault and the 5 cycles after the fault, and stores them in non-volatile memory for the operation and maintenance terminal to read and analyze via Bluetooth or RS485 interface.

[0052] Specifically, the intelligent sensing and control unit also includes a self-identification module. When a new IGBT power control module is inserted into the power control room, the self-identification module automatically identifies its model, rated current, and thermal network parameters by reading the storage chip inside the module, and automatically downloads the corresponding control algorithm to achieve plug-and-play functionality.

[0053] Furthermore, the intelligent sensing and control unit implements a graded temperature control protection strategy, including:

[0054] Level 1: When the predicted junction temperature is below 80°C, maintain the current fan speed or stop operating.

[0055] The second stage involves actively cooling the fan by linearly increasing the PWM duty cycle based on the predicted temperature rise slope when the predicted junction temperature reaches 80°C but is below 100°C using a PID algorithm.

[0056] The third level is when the fan is at full speed and the predicted junction temperature is 100°C but below 125°C, the derating operation strategy is implemented to reduce the switching frequency or output current limit of the IGBT.

[0057] Level 4: When the predicted junction temperature reaches 125℃, the IGBT shutdown protection is immediately triggered, and a fault alarm is uploaded.

[0058] Furthermore, the communication module includes a 4G / 5G full network connectivity module, an HPLC high-speed power line carrier module, and a Bluetooth 5.0 module; the 4G / 5G module is used for remote data interaction with the distribution network automation master station, the HPLC module is used for local communication with the intelligent terminal in the distribution area, and the Bluetooth 5.0 module is used for on-site debugging and data reading by maintenance personnel.

[0059] In addition, the internal busbar system uses tin-plated copper busbars running through the incoming metering compartment, power control compartment, and outgoing compartment to provide electrical connections for the incoming metering module, IGBT power control module, and outgoing module. The outgoing module, which is pluggably installed in the outgoing compartment, contains several outgoing switches.

[0060] The IGBT driver and protection unit integrates hardware-based overcurrent rapid protection, software-based temperature rise prediction protection, and a dynamic dead-time adjustment circuit. This unit uses a magnetically isolated driver chip and incorporates a desaturation detection circuit to achieve nanosecond-level overcurrent protection. This unit is connected to the intelligent sensing and control unit via optical fiber, achieving complete isolation between signal and power.

[0061] The intelligent sensing and control unit dynamically adjusts the drive dead time of the IGBT based on the junction temperature data collected by the first temperature sensor: when the junction temperature is higher than the first threshold, the dead time is increased to reduce switching losses; when the junction temperature is lower than the second threshold, the dead time is reduced to improve the output waveform quality.

[0062] The power control room is equipped with multiple parallel modular guide rails. The bottom of the IGBT power control module is equipped with a slider that mates with the guide rail, the rear end is equipped with a blind-mating power connector, and the front end is equipped with a handle with a self-locking function. After the IGBT power control module is inserted, it automatically establishes an electrical connection with the internal bus system through the blind-mating power connector.

[0063] The temperature control protection method for the modular intelligent sensing energy metering box with integrated IGBT module temperature control protection of the present invention includes the following steps:

[0064] S1. System initialization: Self-test the IGBT power control module, read its factory parameters and initialize the thermal network model.

[0065] S2. Data acquisition: The load current i(t), IGBT module case temperature Tc(t) and ambient temperature Ta(t) are acquired in real time at a sampling rate of not less than 10kHz.

[0066] S3, Junction Temperature Prediction: Input the collected data into the preset Foster fourth-order thermal network model to calculate the current junction temperature and predict the junction temperature change curve Tj_pre(t) within the next 5 seconds.

[0067] S4. Hierarchical decision-making: Execute different control actions based on the maximum value of Tj_pre(t).

[0068] If max[Tj_pre(t)] < 80℃, then execute step S41 to maintain or reduce the fan speed;

[0069] If 80℃≤max[Tj_pre(t)]<100℃, then execute step S42, and linearly increase the fan PWM duty cycle according to the temperature rise slope using the PID algorithm;

[0070] If 100℃≤max[Tj_pre(t)]<125℃ and the fan is already at full speed, then execute step S43 to reduce the IGBT switching frequency or output current limit.

[0071] If max[Tj_pre(t)]≥125℃, then execute step S44 to immediately shut down the IGBT and report the fault.

[0072] S5. Fault waveform recording and uploading: When step S44 is triggered or a sudden change in electrical parameters is detected, the waveform data of 10 cycles before and after the fault is automatically recorded and uploaded to the distribution network master station through the communication module.

[0073] Comparative Example 1

[0074] To verify the technical effects of the present invention, the following comparative examples are provided.

[0075] Comparative setup: A traditional power metering box is used, which integrates IGBTs as switching devices. However, only one exhaust fan is installed on the top of the box, and the fan is controlled by a simple bimetallic temperature switch (turning on when the temperature exceeds 50°C and turning off when the temperature is below 40°C). The IGBT itself only has desaturation overcurrent protection and no intelligent temperature control strategy.

[0076] Test conditions: The power metering box of this embodiment and the comparative metering box were placed in a high-temperature aging chamber at 60°C and subjected to a repeated impact load. Within 1 minute, the power metering box was operated at 100% load for 40 seconds and then at light load for 20 seconds.

[0077] Comparison of test results and effects (e.g.) Figure 3 (As shown)

[0078] Horizontal axis: Time (t)

[0079] Vertical axis: IGBT junction temperature (Tj)

[0080] Curve A (comparative): Under load impact, the curve shows a sharp, large peak, with a high peak temperature.

[0081] Curve B (in this invention): Under load impact, the curve rises gently, the peak value is "flattened", the overall fluctuation range is small, and the highest temperature is significantly lower than that of curve A.

[0082] Annotation area: Mark "Fan pre-acceleration point" on the rising segment of curve B, "Dynamic peak shaving effect" on the peak segment, and "Dilution operation stabilization point" after multiple impacts.

[0083] Comparative Example 1: The internal temperature switch remains closed at 60°C, and the fan runs continuously. However, due to the inability to predict the IGBT junction temperature, during load surges, the IGBT junction temperature rises sharply from 60°C to 100°C, approaching its rated maximum junction temperature, resulting in high thermal cycling stress and poor long-term reliability.

[0084] Embodiments of the present invention:

[0085] Active cooling phase: In the early stage of load impact, the thermoelectric coupling model predicted that the junction temperature would exceed 90°C at 15 seconds. The system increased the fan speed to 80% 10 seconds in advance, successfully suppressing the peak junction temperature below 80°C.

[0086] Derating protection phase: After multiple consecutive impacts, heat accumulation leads to an increase in base temperature. The model predicts that the junction temperature will exceed 80°C during the third impact. The system automatically executes a derating strategy, reducing the output current limit by 15%. Although this sacrifices some instantaneous power, it ensures that the junction temperature always operates within the safe range (<90°C), avoiding sudden shutdown due to overheating and ensuring continuous power supply to critical loads.

[0087] Results: Compared with the comparative example, the junction temperature fluctuation of the IGBT in this invention is reduced by 65%, and the maximum junction temperature is reduced by 10°C, which significantly improves the lifespan of the IGBT module and the continuity of system power supply.

[0088] It should be noted that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A modular intelligent sensing energy metering box integrating IGBT module temperature control protection, characterized in that: The enclosure includes a housing, the interior of which is divided into an incoming line metering chamber, a power control chamber, and an outgoing line chamber by a metal partition. An electromagnetic shielding layer is provided between the power control chamber and the incoming line metering chamber and the outgoing line chamber. The incoming line metering module is pluggably installed in the incoming line metering chamber and includes an incoming line terminal block, an intelligent power metering chip, and a current and voltage sampling unit. At least one IGBT power control module is pluggably installed in the power control room, including an IGBT power unit, for performing circuit on / off control and power quality regulation; An integrated thermal management system includes a heat sink that is thermally connected to the IGBT power unit, a first temperature sensor located near the IGBT chip, a second temperature sensor located at the heat sink outlet, and a variable speed fan driven by an intelligent control unit. The IGBT driver and protection unit integrates hardware-based overcurrent fast protection and software-based temperature rise prediction protection. The outgoing module is pluggably installed in the outgoing room and includes several outgoing switches; The intelligent sensing and control unit is communicatively connected to the incoming line metering module, the IGBT power control module, and the outgoing line module, respectively. It includes a data processing module for receiving voltage, current, and temperature data and performing edge computing; and a thermoelectric coupling prediction module, which embeds a thermal network model of the IGBT module for calculating heat generation based on real-time current and combining it with heat dissipation conditions to dynamically predict the future trend of IGBT junction temperature. The communication module is used to interact with an external master station or maintenance terminal; the intelligent sensing and control unit transmits control signals to the IGBT drive and protection unit through optical fiber to achieve electrical isolation between signal and power. The internal bus system uses tin-plated copper busbars that run through the incoming metering chamber, power control chamber, and outgoing chamber to provide electrical connections for the incoming metering module, IGBT power control module, and outgoing module.

2. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 1, characterized in that: The integrated thermal management system also includes a phase change thermal storage device, which is closely fitted to the radiator to absorb the instantaneous impact heat generation of the IGBT power unit and smooth out temperature fluctuations. The phase change thermal storage device is filled with paraffin-based composite phase change material, and its phase change temperature is set to 85-95℃.

3. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 2, characterized in that: The IGBT drive and protection unit also includes a dynamic dead time adjustment circuit. The intelligent sensing and control unit dynamically adjusts the IGBT drive dead time according to the junction temperature data collected by the first temperature sensor: when the junction temperature is higher than the first threshold, the dead time is increased to reduce switching losses; when the junction temperature is lower than the second threshold, the dead time is reduced to improve the output waveform quality.

4. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 3, characterized in that: The thermal network model embedded in the thermoelectric coupling prediction module is a Foster fourth-order RC network model, with time constants set to τ1=0.1s, τ2=0.5s, τ3=2.0s, and τ4=5.0s, respectively, to simulate the transient thermal response characteristics of the IGBT module; the prediction module updates the junction temperature prediction value at a frequency of 10Hz, and the prediction time domain length is 5 seconds.

5. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 4, characterized in that: The intelligent sensing and control unit also includes a fault recording module. When the IGBT power control module triggers protection or electrical parameters change abruptly, it automatically records the voltage, current and temperature waveform data for the 10 cycles before the fault and the 5 cycles after the fault, and stores them in a non-volatile memory for the operation and maintenance terminal to read and analyze via Bluetooth or RS485 interface.

6. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 5, characterized in that: The power control room is equipped with multiple parallel modular guide rails. The bottom of the IGBT power control module is equipped with a slider that mates with the guide rails, the rear end is equipped with a blind-plug power connector, and the front end is equipped with a handle with a self-locking function. After the IGBT power control module is inserted, it automatically establishes an electrical connection with the internal bus system through the blind-plug power connector.

7. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 6, characterized in that: The intelligent sensing and control unit also includes a self-identification module. When a new IGBT power control module is inserted into the power control room, the self-identification module automatically identifies its model, rated current, and thermal network parameters by reading the storage chip inside the module, and automatically downloads the corresponding control algorithm to achieve plug-and-play functionality.

8. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 7, characterized in that, The intelligent sensing and control unit implements a graded temperature control protection strategy, including: Level 1: When the predicted junction temperature is below 80°C, maintain the current fan speed or stop operating. The second stage involves actively cooling the fan by linearly increasing the PWM duty cycle based on the predicted temperature rise slope when the predicted junction temperature reaches 80°C but is below 100°C using a PID algorithm. The third level is when the fan is at full speed and the predicted junction temperature is 100°C but below 125°C, the derating operation strategy is implemented to reduce the switching frequency or output current limit of the IGBT. Level 4: When the predicted junction temperature reaches 125℃, the IGBT shutdown protection is immediately triggered, and a fault alarm is uploaded.

9. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 8, characterized in that: The communication module includes a 4G / 5G full network connectivity module, an HPLC high-speed power line carrier module, and a Bluetooth 5.0 module. The 4G / 5G module is used for remote data interaction with the distribution network automation master station, the HPLC module is used for local communication with the intelligent terminal in the distribution area, and the Bluetooth 5.0 module is used for on-site debugging and data reading by maintenance personnel.

10. The modular intelligent sensing energy metering box with integrated IGBT module temperature control protection according to claim 9, characterized in that, The temperature control protection method for this modular intelligent sensing energy metering box includes the following steps: S1. System initialization: Self-test the IGBT power control module, read its factory parameters and initialize the thermal network model. S2. Data acquisition: The load current i(t), IGBT module case temperature Tc(t) and ambient temperature Ta(t) are acquired in real time at a sampling rate of not less than 10kHz. S3, Junction Temperature Prediction: Input the collected data into the preset Foster fourth-order thermal network model to calculate the current junction temperature and predict the junction temperature change curve Tj_pre(t) within the next 5 seconds. S4. Hierarchical decision-making: Execute different control actions based on the maximum value of Tj_pre(t). If max[Tj_pre(t)] < 80℃, then execute step S41 to maintain or reduce the fan speed; If 80℃≤max[Tj_pre(t)]<100℃, then execute step S42, and linearly increase the fan PWM duty cycle according to the temperature rise slope using the PID algorithm; If 100℃≤max[Tj_pre(t)]<125℃ and the fan is already at full speed, then execute step S43 to reduce the IGBT switching frequency or output current limit. If max[Tj_pre(t)]≥125℃, then execute step S44 to immediately shut down the IGBT and report the fault. S5. Fault waveform recording and uploading: When step S44 is triggered or a sudden change in electrical parameters is detected, the waveform data of 10 cycles before and after the fault is automatically recorded and uploaded to the distribution network master station through the communication module.

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